Discharger for centrifugal machines



April 7, 1942. J. HERTR-ICH 2,279,235

' DISCHARGE-R FOR CENTRIFUGAL MACHINES Filed Nov. 2, 1 938 2 Sheets-Sheet l DIRECT/ON or BASKET SWING 04/7 INVENTOR a/lesa/o/v 01. z msr/cv DEFLEcT/ON or 5/10: inar/01y 0F sag! JOSEPH HF ATTORNEYS I Y A ril 7, 1942 y '-J.HERTR| H 2,279,235

DISCHARGER FOR JENTRIFUGAL MACHINES Filed NOV. 2, 1938 2 SheetsSheet 2 hnlllljlunllllml ATTORNEYS I'd v Patented Apr. 7, 1942 STATES PATENT orics DISCHARGER lOR CENTRIFUGAL MA HINES Joseph Hertrich, Hamilton, Ohio, assignor to The Western States Machine Company, New York, N Y., a corporation of Utah Application November 2, 1938, Serial No. 238,390

12 Claims.

The dischargers used for unloading sugar centrifugals and the like operate with a plowing action. The scraping plate or tip of the discharger shoe enters the revolving annular layer of material on the basket wall and has a tendency to dig more and more into the material. This tendency is due to torque reactions of the basket under discharging loads and to elastic deflection of the discharger mechanism under stresses imposed by the discharging operation. At times the discharger tip is forced against the basket screens with such pressure that the linings are torn or quickly worn out, which of course is objectionable and a source of considerable expense. Improved dischargers, such as those having adjustablestop screws and pivotally attached scraper'tips (Roberts, U. S. Patent No. 2,076,516), have eliminated some of the dangers encountered in normal operation,but, a very real danger of tearing out the delicate basket lining still exists particularly when a hard load of material is being discharged.

The baskets used in work of this type are of the gyratory suspended type and are susceptible to a certain amount of deflection or swing-out depending directly upon the torque reactions on thebasket spindle. This force is in turn directly proportional to the hardness of the layer of material being discharged and to the speed of revolution of the basket. As long as the hardness of the material and the speed of revolution are constant, the basket deflection or swing-out may remain substantially constant and may be well taken care of by the use of an adjustable stop screw limiting the movement of the scraper toward the centrifugal curb, and of a scraper tip pivotably attached to the discharger shoe. When, however, the hardness'of the layer or the speed of revolution during discharging are subject to variation, which happens in spite of the greatest precautions, the torque reactions on the basket spindlev vary and cause a variable deflection or swing-out of the basket which is notalways taken,

care of by the devices of the prior art. This variation of swing-out, therefore, gives rise to a danger of tearing out the screens or linings of the basket, particularly if the scraper ncfoun-f ters hard material when the set screw limiting its position relative to the basket curb has been set for a soft material.

The heavy strain placed upon the plow and discharger spindle during the discharging operation also causes an elastic deflection of the discharger mechanism which, like basket swing-out, increases directly with the hardness of the ma-' terial being discharged and the speed of revolu-.

tion of the basket. This elastic deflection has objectionable results similar to those caused by the basket swing-out. For example, an increase in the resistance of the material during discharging tends to deflect the discharger shoe toward the adjacent basket wall, in a direction opposite to that taken by the basket when forced to swing out of plumb, thereby adding to the danger'of tearing out the screens or linings of the basket.

An object of my invention is'to provide in centrifu'gal' apparatus a discharger mechanism which eliminates the objectionable basket swing-out that occurs during the use of conventional discharger mechanisms, and which protects the basket linings from avoidable damage by the tip of the discharger shoe during the discharging operation.

Another object of my invention is to provide" a useful force which tends to move the basket wall away from the discharger tip, thereby re-.' ducing thepressure between the discharger tip and the basket screens when the discharger mechanism undergoe elastic deflection under load.

A further object of this invention is to provide an apparatus bywhich objectionable pressure between the tip of the discharger shoe and the basket screens maybe avoided during discharg ing irrespective of the resistance of the charge to the plowing action of the shoe.

I have found that the torque reactions or forces acting on the revolving centrifugal basket or has ket spindle during discharging, which ordinarily are responsible for excessive pressure between the discharger tip and the basket screens and for consequent damage to the screens, can be controlled and utilized to advantage so as to elimi This is accomplished, according to my invention, by'

nate much of the cause for such damage.

providing in association with the centrifugal and its discharger mechanism, a stop or force-con plow is within the basket the flange 62 coacts with and rests upon aledge 68. This locates the bushing on the-discharger shaft in such manner that'the inner rim i .of the basket top and the freely running roller 64 lie in the same horizontal plane. The support 68 for member 66 is preferably constructed so as to prevent swaying motion of the discharger shaft when under load, for example, by making it of 'arcuate shape to engage around member '66 and beneath the flange 62. As the bushing is slidably mounted on the discharger shaft it does not in any way hamper the efiicient use of the discharger'plow, andits separable con- 'nection'with the support 68 permits its removal from operating position with the plow when the plow is lifted from within the basket and swung to a position overlying and resting upon the top wall 22-of the curb.

' When the discharger shoe isin operating position the face H! of the handle H may be turned until it rests against a 'stopscrew 12 which is screwed into lug13 of the discharger bracket and is locked by lock nut 14. This screw can be adjusted so that the discharger tip will just barely touch the basket screen when the discharger shaft is turned to its limiting position. 7 As has been previously stated, during the usual discharging operation, when the plow is digging into the material being discharged, the basket swings in such manner that the basket wall is brought closer to the discharger tip. This is for the most'part due to'a torque reaction, and to the factthat the centrifugal is of the overhead gyratory suspension type to permit safety of operation in the type of work for which it is adapted. The effect of uncontrolled torque reactions, in an apparatus not embodying the present invention, is illustrated diagrammatically in Fig. 5, where P represents the vector of force caused by pressure of the sugar against thedischarger shoe when the discharger is in operation and P represents the vector of force caused by the pressure of sugar on the discharger tip.

Corresponding torque reactions which tend to cause basket swing-out are represented by vectors R and R "the resultant R. representing the direction and intensity of the net reactive force that tends to cause swing-out. Moreover, during the discharging operation the plow and dischargerspindle are under aheavy strain, and as a result there are elastic deflections in the whole discharger mechanism. The direction of the elastic deflection of the discharger shoe is indicated by D The extent of such deflection is of course dependent upon P the pressure exerted on the discharger shoe. In this case it should be figure, R the resultant force arising from'the torque reaction, is largely counteracted {by the fact that the roller or stop member M contacts the rim of the basket cap in a region 'where it opposes that force and so prevents inward swinging movement of the-basket wall against the shoe tip in response to R The extent to which M counteracts R when M is mounted on the discharger shaft, is represented by; vector R. It will be observed that R is not completely absorbed by M when M is so positioned; instead, R and R together result in a small reactive force, represented by vector R in a direction that tends to swing the basket out of plumb in a desirable manner. Any motion of the basket and spindle assembly induced by R takes place in an arc D having an-axis near or atthe point of contact between M and the basket cap. Such motion, instead of drawing the basket more firmly-against the discharger tip, will cause the basket wall to recede therefrom. As the intensity of the reactive forces on the basket assembly increases, due to increased resistance of the material that is being discharged, the value of R 1. e. the force tending to cause alleviating movementof the basket, also increases.

From a study of these two diagrams it can be seen that with an arrangement such as indicated in Fig. 5 the direction of the elastic deflection of the discharger shoe and the swing out of the basket are opposite, so that the basket is actually pressed toward the tip when the tip is pressed toward the basket; therefore any eX- cessive resistance of the material being discharged has a double tendency to cause objectionable tip pressure against the screen; With an arrangement such as indicated in Fig. '6, hownoted that the direction of the force causing basket swing-out (R and the direction of the force causing elastic deflection of the discharger shoe (D are almost directly opposite. As a result of this the basketwall or screen adjacent to the shoe tip tends to" be moved toward the shoe, andthe shoe tip tends to be moved toward the'adjacent basket wall, the combined effect being an objectionable pressure of the tip against the basket screen and danger of ripping out the screen.

In Fig. 6 these same fundamental forces are ever, the reaction of the discharg r tip under the elastic-deflection of the discharger mechanism is in the same direction as the direction of the basket'swing-out. In other'words, when the discharger tip deflects toward the basket wall because of an increase in pressure on the shoe or tip, the basket and spindle react under this same pressure and the adjacent basket wall swings away from the tip. Therefore the'varia! tion in tip pressure on the basket Wallis only the difference between the movement/of the tip under the elastic deflection of the discharger mechanism and the swing-out of the basket. 'As this difference is negligible in a correctly designed discharger, it can be seen that the hardness or variation in hardness of material to be discharged has very little influence on thedischarging operation, and that the damaging or destruction of centrifugal linings may be reduced.

to a minimum by the use of the present invention. i

A further feature of my improved construction resides in the fact that the discharger shaft is supported at two points during use, by sleeve 44 and hub 32 and by bushing 60 and ledge 68, instead of by the single support, used in prior constructions. This has a beneficial influence on the rigidity of the discharger. I i

It will be understood that the embodimentof my invention described in this specification and illustrated by the drawings is only a preferable form of the means for eliminating objectionable torque reactions of the basket and forcounteracting elastic deflection of the discharger mechanism during the discharging operation and -I, therefore, desire a broad interpretation of the invention within the scope and spirit thereof and limi d: only vwths: claims amende I he emovementtwhereby; to move the shoe into ma.-

t rial; carri din: ai ba k t, wh le he. same, i revolving to; discharge the material" therefrom, ansll-me nsymou ed 0.115 he: d sc eer shaft' na it cnt e n a e anl nn r l e of-f e revolving basket. ata; substantially. fixed point adiacent, to. said, shaft, throughout adischarging openation said last recitedmeansbeingoperative o om ensa e o a tic. defle n of: e i ai er'mecha isml n e load y au naa come ns inem v m n ihe: ke z a aw v-i om saidshoe inresponseto-pressure of; the basket contents against said shoe, wherebyto prevent convergence: 0.1 the tight the; shoe and the ad.- j acentl basket wall because. of variations inthe hardnessmf the; materialbeing; discharged.

2.. In combination with; a, centrifugal including a suspended gvratorv basket andv a discharger shaft carrying a; disqharger'shoeadjacent its lower end, meansmounting said discharger shaft on, mixed. verticalaxis. for axial and, turning movement; whereby; to lower the shoe. into the basketand totmove the-shoeinto the contents o f .the;basket while thesame isrevolving, a bush;- ing slidablymounted on-the discharger shaft, -a rollerr carried; bvsaid, bushing, and meansfor hold n said bushing and roller so thatthe roller engages. theginner rim o f .the baskettop: at a fixed point adjacentsaid shaft when-the dis,-

charger shoe is.lowered-,to operating position.

3.,In. combination; a centrifugal including a suspended: gyr'atory basket and asurrounding curb,,a dischargermechanism mounted on said cu including a vertical discharger shaft; and a discharger" shoe thereon adapted to bemoved into thegcontents of saidbasket when theshaft is ..lowered. into I the basket and turned,;.to dis.- ichalfgesuch. contents, abushing slidably, mount- 1 11,, on;lthe discharger shaft; a roller carried by c said, bushin band cooperatingmeans on-said curb and. said; bushing, for holding said roller. in con,-

tact withthe .revolving basket rim-at-a fixed po nt adjacent aid shaft .when the discharger shoeis loweredlto operating position;

i 4. Centrifugal apparatus comprising a suspended, gyratory. basket and asurrounding sta.-

,tionary curb, a, discharger. mechanism mounted on said curbincluding a..vertical .discharger. shaft and a diseharger. shoe, extending radially. there..-

- carried on the lower end of-saidshaft andadaptfrom and adapted to discharge the contents of said basket when the shaft is lowered and turned to direct the shoe into'the revolving basket. contents; and rollermeans mounted on said dis.- charg er-shaftsoas-t0 engage the inner rim of the (revolving basket top at a fixed location during a discharging =opera;tion'= and--operativeduring such operationzto convert-reactive forces on said basket, arising-:from the resistance of the revolving basket :contentsto the. plowing action of said. .shoe, into.) atdirectional force tending, to di'splacethe revolvingbasket wall away-from the tip-nfsaidshoe. i

5;.Centrifugal. apparatus comprising a. sus.- pended: gy-ratory: basket and; a. surrounding star tionary; curb; a.=discharger mechanism mounted n sa d: urb: includ ng: a: vertical; discharee shaieand; adischarger; shoes extending-.- radially therefrom. and adapted; to.- discharge. the contents-,of the-basketwhenzt-he shaft is-loweredand turned to direct the shoeeinto. the revolvingbasv set contents andar roller on saiddischarger. shaft positioned to engage an-,inwardly, facing circular edge. on, the revolving basketdur-ing a. discharging; operation ate. point radially in, line with the ax-isof said basket and said; shaft.

6. In a discharger mechanism for avgyratory centrifugal machine, a discharger shaft adapted to extend. vertically through the openingfin the top, of the centrifugal basket, a discharger shoe ed to be turned by said shaft into the contents of the centrifugal basket, and, roller meansseecured; to-said shaft, above said. shoe.= and adapted to contact theinner rim. of the revolving basket top adjacent said shaft when the discharger is in operative position. l

7. In a discharger mechanism for a. gyratory centrifugal machine, a discharge: shaft adapted to extend, vertically through, the opening in. the top of the centrifugal basket, aydischarger shoe carried onthe ,lower. end of said shaft and adapt: ed, to' be turnedjby saidshaft into .the. contents of the centrifugal basket, a bushing slidably keyed.- to said shaft above said'shoe, a roller mounted on said bushing and adapted to contact the inner rimof the revolving basket top adjacent said shaft when the discharger is in oper-. ative position, and means'for-holding said'bushing and roller in liile. withlthe inner. rim, of the basket topwhen the discharger .is in. operative position.

8. In, combination, a centrifugal including a gyratory basket, a discharger mechanism. ineluding a, vertical 'discharger shaft carrying. a. discharger shoe adjacent its lower end, means mounting. said-shaft on a fixed verticalaxisfor axial and turning movementwherebyto move said shoe into and; to discharge thelcontents of the basket while the same is revolving, andmeans located in a fixed position. onsaid shaft during a. discharging. operation toengage the revolving basket. during. such,operation. at a. fixed. location disposed angularlyaway; from a diametrical vertical plane passing throughl the axis of. said bination, a'suspended gyratory. spindle and basketassembly, a discharger mechanism including a 'discharger shaft. having a discharger. shoe thereon, means, mounting, said shaft for axial and'turning movement on a fixed vertical axis whereby to move said' shoe into and'to discharge the contents of the basket while said assemblyis revolved, and astop member positioned and maintained-atafixed location duringa discharging operationwhereat: said member engages-the revolving assembly and opposes: the: resultant. of reactive; forces on. the assembly that: arise from the. plowing. action ,of the shoe. and. so. prevents swinging movement of; thelrevnlving. basket. wall against th tip of the shoe in response to such forces, said member engaging said assembly only within a limited angular region disposed angularly away from a diametrical vertical plane passing through said tip and the axis of said spindle.

10. In centrifugal apparatus comprising a suspended gyratory spindle and basket assembly and a discharger mechanism including a discharger shaft having a discharger shoe thereon and means mounting said shaft for axial and turning movement on a fixed vertical axis where by to move said shoe into and to discharge the contents of the basket while said assembly is revolved, a stop member positioned at a fixed location during a discharging operation whereat said member engages the revolving assembly, opposes the resultant of reactive forces on the assembly that arise from the plowing action of the shoe and so prevents swinging movement of the revolving basket wall against the tip of the shoe in response to such forces, and means operated as a result of moving said shaft axially to move said shoe into the basket for positioning and maintaining said member at said location, the place of engagement of said member with said assembly being within a limited angular region disposed angularly away from a diametrical vertical plane passing through said tip and the axis of said spindle.

l1. Centrifugal apparatus comprising, in combination, a suspended gyratory basket and spindle assembly, a discharger mechanism including a discharger shaft having a discharger shoe thereon, means mounting said shaft for axial and turning movement on a fixed Vertical axis whereby to move said shoe into and to discharge the contents of the basket while said assembly is revolved, and a stop member positioned and maintained at a fixed location during a discharging operation whereat said member engages the revolving assembly, opposes the resultant of reactive forces on the assembly that arise from the plowing action of the shoe, so preventing swinging movement of the revolving basket Wall against the tip of the shoe in response to such forces, and converts such forces into a directional force tending to displace the revolving basket wall away from said tip, said member engaging said assembly only within a limited angular region disposed angularly away from a diametrical vertical plane passing through said tip and the axis of said spindle.

l2. Centrifugal apparatus comprising, in combination, a suspended gyratory basket and spindle assembly, a discharger mechanism including a discharger shaft having a discharger shoe thereon, means mounting said shaft for axial and turning movement on a fixed vertical axis whereby to move said shoe into and to discharge the contents of the basket while said assembly is revolved, and a stop member positioned and maintained at a fixed location during a discharging operation whereat said member engages the revolving basket, opposes the resultant of reactive forces on the assembly that arise from the plowing action of the shoe, so preventing swinging movement of the revolving basket wall against the tip of the shoe in response to such forces, and converts such forces into a directional force tending to displace the revolving basket wall away from said tip, said member engaging said basket only within a limited angular region disposed angularly away from a diametrical vertical plane passing through said tip and'the axis of said spindle.

JOSEPH HERTRICH. 

